贝类产品镉铜铅锌的含量特征与风险分析

根据2007年和2009年对广东、广西沿海部分海域近江牡蛎（Crassostrea rivularis）、太平洋牡蛎（Crassostrea gigas）、翡翠贻贝（Perna viridis）、菲律宾蛤仔（Ruditapes Philippinarum）和文蛤（Meretrix meretrix）的监测资料,分析了贝类产品中镉（Cd）、铜（Cu）、铅（Pb）、锌（Zn）的含量特征及其季节差异,并采用点估计方法对贝类产品中的Cd、Cu、Zn、Pb进行了风险分析。结果表明,贝类品种的差异决定了其体内Cd、Cu、Pb、Zn含量的差异,近江牡蛎样品中Cd、Cu、Zn的含量远远高于另外4种贝类,文蛤样品中Cd、Cu、Pb的含量明显低于其他4种贝类。贝类产品中Cd、Cu、Pb、Zn的含量存在一定的季节差异,这可能与海水的温度、盐度、溶解氧等因子的季节变化有关。与《无公害食品水产品中有毒有害物质限量》标准的限量值相比,贝类产品中Cd、Cu、Pb的合格率分别为65%、67.7%和100%。与其他海域贝类产品的调查结果相比,此次贝类样品Cd、Cu、Pb、Zn的含量处于正常的波动范围内;与世界卫生组织/联合国粮农组织的食品添加剂联合专家委员会推荐的暂定每周耐受摄入量相比,太平洋牡蛎、翡翠贻贝、菲律宾蛤仔和文蛤的Pb、Cd的膳食暴露量处于安全范围内,而近江牡蛎的Cd膳食暴露量可能存在风险。

The Content Variation Characteristics and Risk Analysis for Cadmium, Copper, Lead and Zinc in Some Species of Shellfish

According to the survey data on the shellfish of Ruditapes Philippinarum, Perna viridis, Crassostrea rivularis, Crassostrea gigas and Meretrix meretrix collected from the coast along South China Sea in 2007 and 2009, the content characteristics and the seasonal variation of cadmium（Cd）, copper（Cu）, lead（Pb） and zinc（Zn） in the samples were discussed, and the risk caused by these trace heavy metals was analyzed using the method of point estimation. The results showed that the contents of Cd, Cu, Pb and Zn changed with the various species of shellfish with the highest contents（except Pb） in Crassostrea rivularis and the lowest contents（except Zn） in Meretrix meretrix. There existed some seasonal variation for the contents of Cd, Cu, Pb and Zn in the shellfish which was due to the changes of environmental factors such as temperature, salt and dissolved oxygen in the seawater. Comparing with the other sea area, the contents of Cd, Cu, Pb and Zn in the shellfish from the present survey fluctuated between the normal levels, which showed most of these trace metals were relatively stable and under the control value issued by the standard of ＂Non-environmental food products-Safe limits for the hazardous chemicals in the aquatic products＂（except Cd and Cu in a small amount of samples）. The risk analysis results showed that the Pb contents in all the shellfish products were in the safe ranges according to the recommended values of the Joint FAO/WHO Expert Committee on Food Additives（JECFA）, and the Cd contents were also in the safe ranges except in the species of Crassostrea rivularis. Judged by the contents of the trace heavy metals, the quality of the shellfish products from the present survey was in the edible security level, and just was the same as the products sold in the city markets.